[PATCH v4 09/10] devres: add devm_memremap

Dan Williams
2015-08-11T03:44:25Z

From: Christoph Hellwig <hch@lst.de>

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
include/linux/io.h | 4 ++++
kernel/memremap.c | 40 ++++++++++++++++++++++++++++++++++++++++
2 files changed, 44 insertions(+)

diff --git a/include/linux/io.h b/include/linux/io.h
index 3fcf6256c088..d8d749abd665 100644
--- a/include/linux/io.h
+++ b/include/linux/io.h
@@ -80,6 +80,10 @@ int check_signature(const volatile void __iomem *io_addr,
const unsigned char *signature, int length);
void devm_ioremap_release(struct device *dev, void *res);

+void *devm_memremap(struct device *dev, resource_size_t offset,
+ size_t size, unsigned long flags);
+void devm_memunmap(struct device *dev, void *addr);
+
/*
* Some systems do not have legacy ISA devices.
* /dev/port is not a valid interface on these systems.
diff --git a/kernel/memremap.c b/kernel/memremap.c
index a293de52e837..1dbe88088aa1 100644
--- a/kernel/memremap.c
+++ b/kernel/memremap.c
@@ -10,6 +10,7 @@
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*/
+#include <linux/device.h>
#include <linux/types.h>
#include <linux/io.h>
#include <linux/mm.h>
@@ -96,3 +97,42 @@ void memunmap(void *addr)
iounmap((void __iomem *) addr);
}
EXPORT_SYMBOL(memunmap);
+
+static void devm_memremap_release(struct device *dev, void *res)
+{
+ memunmap(res);
+}
+
+static int devm_memremap_match(struct device *dev, void *res, void *match_data)
+{
+ return *(void **)res == match_data;
+}
+
+void *devm_memremap(struct device *dev, resource_size_t offset,
+ size_t size, unsigned long flags)
+{
+ void **ptr, *addr;
+
+ ptr = devres_alloc(devm_memremap_release, sizeof(*ptr), GFP_KERNEL);
+ if (!ptr)
+ return NULL;
+
+ addr = memremap(offset, size, flags);
+ if (addr) {
+ *ptr = addr;
+ devres_add(dev, ptr);
+ } else
+ devres_free(ptr);
+
+ return addr;
+}
+EXPORT_SYMBOL(devm_memremap);
+
+void devm_memunmap(struct device *dev, void *addr)
+{
+ WARN_ON(devres_destroy(dev, devm_memremap_release, devm_memremap_match,
+ addr));
+ memunmap(addr);
+}
+EXPORT_SYMBOL(devm_memunmap);
+